Enhanced Electrical Performance of Ultrathin Body Nanosheets

Ultrathin body has the immunity to subthreshold swing (SS) degradation by doping and D
it
, approaching the ideal SS of 60mV/dec. The large effective bandgap (E
g
) by the quantum confinement results in high I
ON
/I
OFF
. The large E
g
weakens the impact ionization to improve the high breakdown voltage. The Ge
0.9
Sn
0.1
ultrathin bodies are realized by co-optimization between CVD epitaxy and etching. The nearly ideal SS of 64mV/dec is achieved. The compressive strain of GeSn channel after channel release increases with decreasing body thickness. The ~2nm ultrathin body has a compressive strain of 3.3%. The high breakdown voltage of 11.7V is also achieved, as compared to 6V breakdown voltage of 10nm nanosheets.